But producers of organic milk are required to allow their cows to spend a certain amount of time grazing on pastures free of pesticides, and that natural diet does produce a noticeable effect on the fatty acids in the milk. Compared with conventional milk, organic milk has been shown to have lower levels of omega-6 fatty acids, which are believed to be unhealthy for the heart in high concentrations, and higher levels of the healthful omega-3 fatty acids. While the Stanford researchers noted that organic milk does have "modestly higher" levels of omega-3 fatty acids, Organic Valley, a cooperative of organic farmers in the USA, says its organic milk shows omega-3 levels that are 79 percent higher than those in conventional milk, as well as much lower levels of "bad" omega-6. The truth is somewhere between but still very positive vote for organic milk. We are just so used to "homogenised", and get a bit put off by the globules of fat in tea when you use organic milk - but this is actually good for you.